I've been implementing a Go client library for the Backblaze B2 cloud storage service: go-backblaze. It works extremely well, but is a bit slow to get files back.
I've implemented a parallel download feature which you can use to download several files at the same time - this doesn't seem to affect the speed of individual downlaods very much, so I assume that the downloads are limited for one of two reasons
- There is a download speed cap in place
- The downloads each come from separate parts of the cluster file system, and so don't affect each other.
Downloading 5 copies of the same file in parallel doesn't seem to affect the download speed, nor do 5 sequential downloads. Whatever you do, each download seems to run at about 200KiB/sec.